package net.shadowfacts.cacao.util

import com.mojang.blaze3d.systems.RenderSystem
import net.minecraft.client.MinecraftClient
import net.minecraft.client.gui.DrawableHelper
import net.minecraft.client.gui.screen.Screen
import net.minecraft.client.render.*
import net.minecraft.client.sound.PositionedSoundInstance
import net.minecraft.client.util.math.MatrixStack
import net.minecraft.sound.SoundEvent
import net.minecraft.text.LiteralText
import net.minecraft.text.OrderedText
import net.minecraft.text.Text
import net.minecraft.util.math.Matrix4f
import net.shadowfacts.cacao.geometry.Point
import net.shadowfacts.cacao.geometry.Rect
import net.shadowfacts.cacao.util.texture.Texture
import kotlin.math.roundToInt

/**
 * Helper methods for rendering using Minecraft's utilities from Cacao views.
 * For unit testing, all drawing and OpenGL interaction can be disabled by setting the `cacao.drawing.disabled` JVM property to `true`.
 *
 * @author shadowfacts
 */
object RenderHelper: DrawableHelper() {

	val disabled = (System.getProperty("cacao.drawing.disabled") ?: "false").toBoolean()

	// TODO: find a better place for this
	fun playSound(event: SoundEvent) {
		if (disabled) return
		MinecraftClient.getInstance().soundManager.play(PositionedSoundInstance.master(event, 1f))
	}

	/**
	 * Draws a solid [rect] filled with the given [color].
	 */
	fun fill(matrixStack: MatrixStack, rect: Rect, color: Color) {
		if (disabled) return
		fill(matrixStack, rect.left.toInt(), rect.top.toInt(), rect.right.toInt(), rect.bottom.toInt(), color.argb)
	}

	/**
	 * Binds and draws the given [texture] filling the [rect].
	 */
	fun draw(matrixStack: MatrixStack, rect: Rect, texture: Texture) {
		if (disabled) return
		RenderSystem.setShader(GameRenderer::getPositionTexShader)
		RenderSystem.setShaderTexture(0, texture.location)
		draw(matrixStack, rect.left, rect.top, texture.u, texture.v, rect.width, rect.height, texture.width, texture.height)
	}

	fun drawLine(start: Point, end: Point, z: Double, width: Float, color: Color) {
		if (disabled) return

		RenderSystem.lineWidth(width)
		val tessellator = Tessellator.getInstance()
		val buffer = tessellator.buffer
		buffer.begin(VertexFormat.DrawMode.LINES, VertexFormats.POSITION_COLOR)
		buffer.vertex(start.x, start.y, z).color(color).next()
		buffer.vertex(end.x, end.y, z).color(color).next()
		tessellator.draw()
	}

	/**
	 * Draws the bound texture with the given screen and texture position and size.
	 */
	fun draw(matrixStack: MatrixStack, x: Double, y: Double, u: Int, v: Int, width: Double, height: Double, textureWidth: Int, textureHeight: Int) {
		if (disabled) return
		val uStart = u.toFloat() / textureWidth
		val uEnd = (u + width).toFloat() / textureWidth
		val vStart = v.toFloat() / textureHeight
		val vEnd = (v + height).toFloat() / textureHeight
		drawTexturedQuad(matrixStack.peek().positionMatrix, x, x + width, y, y + height, 0.0, uStart, uEnd, vStart, vEnd)
	}

	// Copied from net.minecraft.client.gui.DrawableHelper
	// TODO: use an access transformer to just call minecraft's impl
	private fun drawTexturedQuad(matrix: Matrix4f, x0: Double, x1: Double, y0: Double, y1: Double, z: Double, u0: Float, u1: Float, v0: Float, v1: Float) {
		val bufferBuilder = Tessellator.getInstance().buffer
		bufferBuilder.begin(VertexFormat.DrawMode.QUADS, VertexFormats.POSITION_TEXTURE)
		bufferBuilder.vertex(matrix, x0.toFloat(), y1.toFloat(), z.toFloat()).texture(u0, v1).next()
		bufferBuilder.vertex(matrix, x1.toFloat(), y1.toFloat(), z.toFloat()).texture(u1, v1).next()
		bufferBuilder.vertex(matrix, x1.toFloat(), y0.toFloat(), z.toFloat()).texture(u1, v0).next()
		bufferBuilder.vertex(matrix, x0.toFloat(), y0.toFloat(), z.toFloat()).texture(u0, v0).next()
		bufferBuilder.end()
		BufferRenderer.draw(bufferBuilder)
	}

	fun drawTooltip(matrixStack: MatrixStack, text: Text, mouse: Point) {
		drawTooltip(matrixStack, listOf(text.asOrderedText()), mouse)
	}

	fun drawTooltip(matrixStack: MatrixStack, texts: List<Text>, mouse: Point) {
		drawTooltip(matrixStack, texts.map(Text::asOrderedText), mouse)
	}

	private val dummyScreen = object: Screen(LiteralText("")) {
		init {
			textRenderer = MinecraftClient.getInstance().textRenderer
			itemRenderer = MinecraftClient.getInstance().itemRenderer
		}
	}

	@JvmName("drawOrderedTooltip")
	fun drawTooltip(matrixStack: MatrixStack, texts: List<OrderedText>, mouse: Point) {
		if (disabled) return
		if (texts.isEmpty()) return

		val client = MinecraftClient.getInstance()
		dummyScreen.width = client.window.scaledWidth
		dummyScreen.height = client.window.scaledHeight
		dummyScreen.renderOrderedTooltip(matrixStack, texts, mouse.x.roundToInt(), mouse.y.roundToInt())
	}

	/**
	 * @see org.lwjgl.opengl.GL11.glColor4f
	 */
	fun color(r: Float, g: Float, b: Float, alpha: Float) {
		if (disabled) return
		RenderSystem.setShaderColor(r, g, b, alpha)
	}

	private fun VertexConsumer.color(color: Color): VertexConsumer {
		return color(color.red, color.green, color.blue, color.alpha)
	}

}